LA police used nearly a dozen undercover detectives to infiltrate the Occupy LA encampment in the weeks before Wednesday's raid to learn about plans of resistance and the location of any weapons that might be used against police.

An official, speaking on condition of anonymity, said none of the officers slept at the camp, but blended in with the protesters during the day. The undercover work yielded information that some protesters were preparing bamboo spears and other potentially dangerous weapons in preparation for an expected eviction by the LAPD.

Police have been using different techniques to disperse the Occupy Movement protesters all over the US. Some of the most violent include brutal dispersals, with tear gas, sound cannons (LRAD) and pepper spray used against peaceful protesters. Although undercover detectives are something of a novelty, the demonstrators have not been surprised by the revelation, calling it a "tantamount to 1950s McCarthyism," as cited by the City News Service.

Nearly 300 people were arrested Wednesday during the pre-dawn raid as 1,400 police officers, some in riot gear, moved in to dismantle the Occupy LA City Hall Camp.

The police stepped in after about half of some 500 tents remained in Los Angles after the Monday morning eviction deadline for the weeks-old encampment – one of the largest still remaining in the country. Officers in helmets and wielding batons and guns with rubber bullets converged on the park from all directions with military precision and began making arrests after several orders were given to for the protesters to leave.

In all, 46 of the 291 people arrested during the raid have been charged with misdemeanor crimes of failure to disperse from an unlawful assembly. Some also were charged with resisting arrest.Fifty-eight posted bail or have been released by police, an additional 187 protesters were released without bail and without being charged, as they had no prior criminal records.

Los Angeles Police Chief Charlie Beck praised the officers and the protesters for their restraint and the peaceful way the eviction was carried out.

Meanwhile, police officials are downplaying the significance of the undercover work, saying Occupy meetings were public and information about their plans was easily attainable.